Implement .ndo_tx_timeout for MANA so any stalled TX queue can be detected
and a device-controlled port reset for all queues can be scheduled to a
ordered workqueue. The reset for all queues on stall detection is
recomended by hardware team.
The change introduces a single ordered workqueue
("mana_per_port_queue_reset_wq") with WQ_UNBOUND | WQ_MEM_RECLAIM and
queues exactly one work_struct per port onto it. This achieves:
* Global FIFO across all port reset requests (alloc_ordered_workqueue).
* Natural per-port de-duplication: the same work_struct cannot be
queued twice while pending/running.
* Avoids hogging a per-CPU kworker for long, may-sleep reset paths
(WQ_UNBOUND).
* Guarantees forward progress during memory pressure
(WQ_MEM_RECLAIM rescuer).
Reviewed-by: Haiyang Zhang <[email protected]>
Signed-off-by: Dipayaan Roy <[email protected]>
---
Changes in v2:
- Fixed cosmetic changes.
---
drivers/net/ethernet/microsoft/mana/mana_en.c | 82 +++++++++++++++++++
include/net/mana/gdma.h | 6 +-
include/net/mana/mana.h | 15 ++++
3 files changed, 102 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c
b/drivers/net/ethernet/microsoft/mana/mana_en.c
index f4fc86f20213..05b7046ae3b5 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -258,6 +258,45 @@ static int mana_get_gso_hs(struct sk_buff *skb)
return gso_hs;
}
+static void mana_per_port_queue_reset_work_handler(struct work_struct *work)
+{
+ struct mana_queue_reset_work *reset_queue_work =
+ container_of(work, struct mana_queue_reset_work, work);
+ struct mana_port_context *apc = reset_queue_work->apc;
+ struct net_device *ndev = apc->ndev;
+ struct mana_context *ac = apc->ac;
+ int err;
+
+ if (!rtnl_trylock()) {
+ /* Someone else holds RTNL, requeue and exit. */
+ queue_work(ac->per_port_queue_reset_wq,
+ &apc->queue_reset_work.work);
+ return;
+ }
+
+ /* Pre-allocate buffers to prevent failure in mana_attach later */
+ err = mana_pre_alloc_rxbufs(apc, ndev->mtu, apc->num_queues);
+ if (err) {
+ netdev_err(ndev, "Insufficient memory for reset post tx stall
detection\n");
+ goto out;
+ }
+
+ err = mana_detach(ndev, false);
+ if (err) {
+ netdev_err(ndev, "mana_detach failed: %d\n", err);
+ goto dealloc_pre_rxbufs;
+ }
+
+ err = mana_attach(ndev);
+ if (err)
+ netdev_err(ndev, "mana_attach failed: %d\n", err);
+
+dealloc_pre_rxbufs:
+ mana_pre_dealloc_rxbufs(apc);
+out:
+ rtnl_unlock();
+}
+
netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
enum mana_tx_pkt_format pkt_fmt = MANA_SHORT_PKT_FMT;
@@ -762,6 +801,25 @@ static int mana_change_mtu(struct net_device *ndev, int
new_mtu)
return err;
}
+static void mana_tx_timeout(struct net_device *netdev, unsigned int txqueue)
+{
+ struct mana_port_context *apc = netdev_priv(netdev);
+ struct mana_context *ac = apc->ac;
+ struct gdma_context *gc = ac->gdma_dev->gdma_context;
+
+ netdev_warn(netdev, "%s(): called on txq: %u\n", __func__, txqueue);
+
+ /* Already in service, hence tx queue reset is not required.*/
+ if (gc->in_service)
+ return;
+
+ /* Note: If there are pending queue reset work for this port(apc),
+ * subsequent request queued up from here are ignored. This is because
+ * we are using the same work instance per port(apc).
+ */
+ queue_work(ac->per_port_queue_reset_wq, &apc->queue_reset_work.work);
+}
+
static int mana_shaper_set(struct net_shaper_binding *binding,
const struct net_shaper *shaper,
struct netlink_ext_ack *extack)
@@ -844,7 +902,9 @@ static const struct net_device_ops mana_devops = {
.ndo_bpf = mana_bpf,
.ndo_xdp_xmit = mana_xdp_xmit,
.ndo_change_mtu = mana_change_mtu,
+ .ndo_tx_timeout = mana_tx_timeout,
.net_shaper_ops = &mana_shaper_ops,
+
};
static void mana_cleanup_port_context(struct mana_port_context *apc)
@@ -3218,6 +3278,7 @@ static int mana_probe_port(struct mana_context *ac, int
port_idx,
ndev->min_mtu = ETH_MIN_MTU;
ndev->needed_headroom = MANA_HEADROOM;
ndev->dev_port = port_idx;
+ ndev->watchdog_timeo = MANA_TXQ_TIMEOUT;
SET_NETDEV_DEV(ndev, gc->dev);
netif_set_tso_max_size(ndev, GSO_MAX_SIZE);
@@ -3255,6 +3316,11 @@ static int mana_probe_port(struct mana_context *ac, int
port_idx,
debugfs_create_u32("current_speed", 0400, apc->mana_port_debugfs,
&apc->speed);
+ /* Initialize the per port queue reset work.*/
+ apc->queue_reset_work.apc = apc;
+ INIT_WORK(&apc->queue_reset_work.work,
+ mana_per_port_queue_reset_work_handler);
+
return 0;
free_indir:
@@ -3456,6 +3522,15 @@ int mana_probe(struct gdma_dev *gd, bool resuming)
if (ac->num_ports > MAX_PORTS_IN_MANA_DEV)
ac->num_ports = MAX_PORTS_IN_MANA_DEV;
+ ac->per_port_queue_reset_wq =
+ alloc_ordered_workqueue("mana_per_port_queue_reset_wq",
+ WQ_UNBOUND | WQ_MEM_RECLAIM);
+ if (!ac->per_port_queue_reset_wq) {
+ dev_err(dev, "Failed to allocate per port queue reset
workqueue\n");
+ err = -ENOMEM;
+ goto out;
+ }
+
if (!resuming) {
for (i = 0; i < ac->num_ports; i++) {
err = mana_probe_port(ac, i, &ac->ports[i]);
@@ -3528,6 +3603,8 @@ void mana_remove(struct gdma_dev *gd, bool suspending)
*/
rtnl_lock();
+ cancel_work_sync(&apc->queue_reset_work.work);
+
err = mana_detach(ndev, false);
if (err)
netdev_err(ndev, "Failed to detach vPort %d: %d\n",
@@ -3547,6 +3624,11 @@ void mana_remove(struct gdma_dev *gd, bool suspending)
free_netdev(ndev);
}
+ if (ac->per_port_queue_reset_wq) {
+ destroy_workqueue(ac->per_port_queue_reset_wq);
+ ac->per_port_queue_reset_wq = NULL;
+ }
+
mana_destroy_eq(ac);
out:
mana_gd_deregister_device(gd);
diff --git a/include/net/mana/gdma.h b/include/net/mana/gdma.h
index 57df78cfbf82..1f8c536ba3be 100644
--- a/include/net/mana/gdma.h
+++ b/include/net/mana/gdma.h
@@ -591,6 +591,9 @@ enum {
/* Driver can self reset on FPGA Reconfig EQE notification */
#define GDMA_DRV_CAP_FLAG_1_HANDLE_RECONFIG_EQE BIT(17)
+/* Driver detects stalled send queues and recovers them */
+#define GDMA_DRV_CAP_FLAG_1_HANDLE_STALL_SQ_RECOVERY BIT(18)
+
#define GDMA_DRV_CAP_FLAGS1 \
(GDMA_DRV_CAP_FLAG_1_EQ_SHARING_MULTI_VPORT | \
GDMA_DRV_CAP_FLAG_1_NAPI_WKDONE_FIX | \
@@ -599,7 +602,8 @@ enum {
GDMA_DRV_CAP_FLAG_1_DEV_LIST_HOLES_SUP | \
GDMA_DRV_CAP_FLAG_1_DYNAMIC_IRQ_ALLOC_SUPPORT | \
GDMA_DRV_CAP_FLAG_1_SELF_RESET_ON_EQE | \
- GDMA_DRV_CAP_FLAG_1_HANDLE_RECONFIG_EQE)
+ GDMA_DRV_CAP_FLAG_1_HANDLE_RECONFIG_EQE | \
+ GDMA_DRV_CAP_FLAG_1_HANDLE_STALL_SQ_RECOVERY)
#define GDMA_DRV_CAP_FLAGS2 0
diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index 0921485565c0..e0b44ae2226a 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -67,6 +67,11 @@ enum TRI_STATE {
#define MANA_RX_FRAG_ALIGNMENT 64
+/* Timeout value for Txq stall detection & recovery used by ndo_tx_timeout.
+ * The value is chosen after considering fpga re-config scenarios.
+ */
+#define MANA_TXQ_TIMEOUT (15 * HZ)
+
struct mana_stats_rx {
u64 packets;
u64 bytes;
@@ -475,13 +480,23 @@ struct mana_context {
struct mana_eq *eqs;
struct dentry *mana_eqs_debugfs;
+ struct workqueue_struct *per_port_queue_reset_wq;
struct net_device *ports[MAX_PORTS_IN_MANA_DEV];
};
+struct mana_queue_reset_work {
+
+ /* Work structure */
+ struct work_struct work;
+ /* Pointer to the port context */
+ struct mana_port_context *apc;
+};
+
struct mana_port_context {
struct mana_context *ac;
struct net_device *ndev;
+ struct mana_queue_reset_work queue_reset_work;
u8 mac_addr[ETH_ALEN];
--
2.43.0
